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<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>

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<script>
    let data = {
        name: '尚硅谷',
        address: '北京'
    }

    // 创建一个监视的实例对象，用于监视 data 中属性的变化
    const obs = new Observer(data)
    console.log(obs)

    // 准备一个 vm 实例对象
    let vm = {}
    vm._data = data = obs

    function Observer(obj) {
        // 汇总对象中所有的属性行程一个数组
        const keys = Object.keys(obj)
        // 遍历
        keys.forEach((k) => {
            Object.defineProperty(this, k, {
                get() {
                    return obj[k]
                },
                set(val) {
                    console.log('${k}被改了');
                    obj[k] = val
                }
            })
        })
    }
</script>

</html>